Math Methods Devised to Design Chemical Catalysts

Matt Sigman (Ryan Deluca, University of Utah)

Research chemists at University of Utah in Salt Lake City have developed a process based on mathematics to design chemical catalysts, including those for making drugs. Professor Matt Sigman (pictured right) and doctoral student Kaid Harper report their findings in this week’s issue of the journal Science; paid subscription required.

Catalysts are substances that encourage or hasten chemical reactions, without being consumed by those reactions. They are the basis of 90 percent of industrial chemical processes in the U.S., including the manufacture of many medicines, fuels, foods and fertilizers. Making catalysts more efficient can thus improve the efficiency of the industries using the catalysts, including reductions in their energy consumption and greenhouse gas (CO2) emissions.

The research by Sigman and Harper, funded by the National Science Foundation, developed a new method to identify and design “asymmetric catalysts,” which are catalyst molecules considered either left-handed or right-handed because they are physically asymmetrical, a chemical property known as chirality.

Using an asymmetric catalyst is often desirable because it helps create molecules with the same handedness or chirality as the catalyst. This property is particularly useful in drug development, where as Sigman notes, “Handedness is an essential component of a drug’s effectiveness.” Drugs generally work by latching onto proteins involved in a disease-causing process, thus drugs with a similar handedness of their target proteins are more likely to work faster and with greater effectiveness.

Producing asymmetric catalysts has been the problem, however, since they required time consuming trial-and-error methods. Sigman and Harper devised a different and more structured process.

Their process uses mathematics to find the optimal size and electronic properties of the candidate catalysts. By combining principles of data analysis with catalyst design, the researchers created a set of nine related catalysts called quinoline proline ligands. They then tested the nine catalysts to determine how well their degree of handedness would be passed on to the chemical reaction products the catalysts were used to produce.

Sigman and Harper discovered that the sizes and electronic properties of catalysts interact to affect how well a catalyst performs, and are not independent factors as was thought. “This study shows quantitatively that the two factors are related,” says Sigman, “and knowing that will make it easier to design many future catalysts.”

Read more: New Techniques Developed to Bind Peptides, Proteins

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